有序链表转换为平衡二叉树(BST)

有序单链表转换为平衡二叉树。

TreeNode *buildTree(ListNode *&list,int n){if (n == 0)return NULL;TreeNode *root = new TreeNode(0);root->left = buildTree(list,n / 2);root->val = list->val;list = list->next;root->right = buildTree(list,n - n / 2 - 1);return root;}TreeNode* sortedListToBST(ListNode* head) {int size = 0;ListNode *p = head;while (p){size++;p = p->next;}p = head;ListNode *list = head;return buildTree(list,size);}